The present invention relates generally to wall structures and in particular to wall structures for post-and-log construction.
Log construction has been known for many decades as typified by the log cabin. For many years the logs have been notched so that at a corner logs forming one wall of a structure can be laid on top of and at an angle alternating with logs from an intersecting wall. In practical use, such construction is usually limited to right angle corners because of the complexity of the angled notches required for non-right angle corners. More recently, posts have been introduced that can be milled with longitudinal faces at a range of desirable angles such that wall members having square-cut ends can be attached by spikes to the posts to form right-angle or non-right angle corners. Although a number of materials may be used to form the “logs” used as wall members, including various types of composite materials, the wall members are typically milled from wood. The term “logs” will be used throughout this disclosure to include all types of materials that simulate a horizontal wooden log and includes different cross sections, either machined, hand-hewn or in a natural state.
To form a tight connection between die logs and the posts, split key members have been used that engage cooperating undercut recesses in the end of the log and a face of the post. In U.S. Pat. No. 6,050,033 there is disclosed a spline arrangement in which the log and post are connected by a key formed by a pair of wedges. The key is expandable and secured the log to the post. A first section of the key member is fitted into place to engage the recesses in the post and the log and then a second section of the key member is inserted and tapped into place beside the first section of the key member. The cross-sections of the split key member are wedge-shaped and tighten the joint as the second portion of the key member is tapped into place.
It is necessary to ensure that the interconnecting butt joints are tight and provide an effective seal, but at the same time accommodate relative movement between logs whilst maintaining a seal. This is particularly an issue in wooden log construction because of the shrinkage of the logs as they dry. This causes the logs to settle and move vertically down. However, in some circumstances the connection of the key to both the log and the post as shown in U.S. Pat. No. 6,050,033 may inhibit such movement and as a result a gap is created between adjacent logs in the log walls.
It is an object of the present invention to obviate or mitigate the above disadvantages.